Tu, in U.S. Pat. No. 4,319,811, disclosed radiation curing coating compositions of suitable viscosities for convenient application to various substrates as coatings having superior abrasion resistance and excellent adhesion properties. These coatings were obtained from a composition of a tri- or tetraacrylate monomer and a diluent monomer which was an N-vinyl lactam such as N-vinylpyrrolidone or N-vinylcaprolactam.
Crivello, in Proc. Rad. Curing VI, Sep. 20-23, 1982, disclosed radiation curable compositions consisting of 50% by weight of trimethylol propane triacrylate and 50% by weight of hexanediol divinyl ether.
Vara and Dougherty, in Rad Tech Europe, Conference Papers, Florence, Italy, October 9-11, 1989, described the preparation of radiation curable compositions consisting of epoxy acrylate and urethane acrylate resins and a 1:1 mixture of the divinyl ether of cyclohexane/dimethanol and the vinyl ether of triethylene glycol.
However, it has been found that these and other available coatings are not particularly water-resistant which causes a curl problem when applying the coated polyester films to a window glass substrate by means of a water-activatable adhesive.
Accordingly, it is an object of this invention to provide a radiation curable coating which has superior abrasion resistance and excellent water resistance.
A feature of the present invention is the provision of a radiation curable composition, in defined compositional ranges, which comprises a radiation curable monomer which is a multifunctional acrylate monomer and a reactive divinyl ether diluent monomer which has a hydrophobic component which includes both water-resistant and abrasion-resistant moieties, the combination of both monomers affording coatings which exhibit excellent abrasion-resistance, adherence to substrates, rapid curing and water-resistance.
These and other objects and features of the invention will be made apparent from the following more particular description of the invention.